1. Technical Field
The present invention relates to an adapter board and a method for manufacturing thereof, a probe card and a method for inspecting a semiconductor wafer using thereof, and a method for manufacturing a semiconductor device.
2. Related Art
In recent years, high-density installation in a semiconductor device requires an increased number of lands disposed in one chip. In particular, configurations of flip-chip devices are advantageous for achieving an arrangement of larger number of lands, since such configurations allow installing lands in array-like patterns in both the periphery of the semiconductor device and additionally the entire surface of the semiconductor device.
In such flip-chip devices, bumps are formed on the lands, which are formed on the semiconductor element via a semiconductor process, by printing, vapor deposition, plating processes or the like. A dicing process is conducted for the obtained product, and then the diced products are installed on the package substrate via a reflow soldering process to complete the production of the device.
An operability of a semiconductor device for a desired operation is required to be checked in a wafer-condition. A large scale integration (LSI) tester is a device for applying electrical signal to a semiconductor wafer having LSI formed therein and determining whether the signal from the LSI to be tested is a desired signal or not. A probe card is a tool utilized between a LSI tester and a semiconductor wafers and serves as transferring electrical signal. Typical probe card includes a probe card board for providing a coupling with a LSI tester and probes for providing contacts with lands on the semiconductor wafer.
In the case of the flip-chip device, the probes are required to be arranged in a probe card board in an array-like pattern with the same spacing as the spacing for the lands in the semiconductor wafer. In addition, a number of lands cause narrower inter-pad distance. When a testing of an LSI for such flip-chip device is conducted, electric contacts are assured by pushing the probes over bumps formed in the lands on the semiconductor wafer.
Coupling terminals that provides coupling to an LSI tester are required to be arranged around the circumference of the surface of the probe card board at predetermined spacing. In addition, coupling terminals that provides coupling to the probes are required to be arranged around the center of the back surface of the probe card board in the same arrangement as employed for the lands on the semiconductor wafer. Therefore, it is concluded that, when the inter-probe distance or probe spacing is different from the inter-terminal distance or terminal spacing for the coupling terminals in the LSI tester, it is necessary to provides a matching of the spacing in the probe card board.
To solve the problem, either a wiring-system or an adapter board-system is employed for converting the spacing.
In the wiring-system, wires are laced through the board, which includes through holes corresponding to the spacing of the land pads in the semiconductor device, and the wires are cut and polished in the back surface of the board, and the cross sections of the wires are employed as the land pads in the side of the probes. The other ends of the wires are connected to the probe card board to obtain the coupling between the LSI tester and the probe.
In the case of employing the wiring system, all the procedures for electric wirings are made by manual works of workers. Limited number of electric wirings is available in the wiring system by such reasons, and more specifically the upper limit would be about 2000 pins.
Therefore, when more pads are required, the use of the adapter board system is required. In order to manufacture land pads that accommodates narrower inter-pad distance of several hundred micrometers, ceramic boards or built-up boards are generally employed for the base material in the adapter board system. The set of the land pads are formed in the side of the back surface of the adapter board at the same spacing as employed in the semiconductor device, and the other set of the land pads are formed in the side of the front surface thereof at the spacing of about 1 mm, and wiring couplings are made between the set of land pads in the side of the back surface and the set of the land pads in the side of the front surface in the inside of the adapter board.
Technologies disclosed in Japanese Patent Laid-Open No. H07-301,642 (1995), Japanese Patent Laid-Open No. 2007-171,140 and Japanese Patent Domestic Publication for PCT Application 2002-531,836 are typically known as probe cards employing the adapter board system.
However, the conventional technologies described above are needed to be improved in the following reasons. More specifically, new adapter board dedicated for the product must be designed in accordance with the arrangement of the pads specified for the product. Ceramics boards and the built-up boards, which are the materials for the base material in the adapter board system, are expensive, and therefore the adapter board system is not advantageous in terms of the costs.
To solve the problem, the technology employing the package substrate of the device as the adapter board has been developed, as described in Japanese Patent Laid-Open No. H07-301,642. The use of the package substrate for the adapter board allows reducing the cost for designing the dedicated board for the device. FIG. 8 shows an exemplary implementation that employs a package substrate for an adapter board. In this example, the configuration of utilizing the product package substrate of the associated device for the adapter board is employed.
On the other hand, the alignment of the land pads of the device with the probes is difficult in the case of the simple utilization of the package substrate of the device for the adapter board.
The situation will be fully described in reference to FIGS. 9A and 9B. FIGS. 9A and 9B illustrate an exemplary implementation of a conventional adapter board that utilizes a package substrate. FIG. 9A shows a cross-sectional view of a conventional adapter board, and FIG. 9B is an enlarged diagram of a portion surrounded by a dotted line in FIG. 9A. A resist 701 is applied over a surface in the side of the testing object of the adapter board 706 (device side in FIG. 9). Since the resist 701 covers the circumference portions of the pads 303, the dimensions of the openings, which are capable of being in contact with the probes, are slightly smaller than the original dimensions of the pads. The trend of reduced inter-pad distance in the semiconductor element provide smaller dimension of the opening of the pad. Therefore, the accuracy required for aligning the pads on the adapter board with the probes are extremely high, and thus the use of such technology is difficult.
In addition, the larger thickness of the resist 701 causes the recessed feature of the pads 303 from the surface of the package substrate. Thus, the upper end of the probe interferes 701 the portion of the resist, causing a concern of deterioration of the nature of the contacts between the probes and the land pads.